Representing in one chart two plots in different axes using ggplot

Question

Let\'s reproduce the example we are working with:

chol <- read.table(url(\"http://assets.datacamp.com/blog_assets/chol.txt\"), header = TRUE)

<

Answer 1

You can try following. Although I'm not understanding the sense of such overplotting.

plot1 <- ggplot(data=chol, aes(AGE)) + 
  geom_histogram(breaks=seq(20, 50, by = 2), 
                 col="red", 
                 fill="green", 
                 alpha = .2) + 
  labs(x="Age", y="Count") + 
  xlim(c(18,52)) + 
  ylim(c(0,100))

plot2 <- ggplot(data=chol, aes(WEIGHT)) + 
  geom_histogram() + 
  labs(x="Weigth", y="Count") +
  scale_x_continuous(position = "top")+
  scale_y_reverse(position = "right",limits = c(50,0)) +
  coord_flip()

library(cowplot)
ggdraw(plot1) + 
  draw_plot(plot2)

Answer 2

I use the code of next blog and I adapted to your example. You have both histograms in one chart, and also a scatterplot.But instead to be infront off they are back to back.

http://sas-and-r.blogspot.com/2011/06/example-841-scatterplot-with-marginal.html

scatterhist = function(x, y, xlab="", ylab=""){
zones=matrix(c(2,0,1,3), ncol=2, byrow=TRUE)
layout(zones, widths=c(4/5,1/5), heights=c(1/5,4/5))
xhist = hist(x, plot=FALSE)
yhist = hist(y, plot=FALSE)
top = max(c(xhist$counts, yhist$counts))
par(mar=c(3,3,1,1))
plot(x,y)
par(mar=c(0,3,1,1))
barplot(xhist$counts, axes=FALSE, ylim=c(0, top), space=0)
par(mar=c(3,0,1,1))
barplot(yhist$counts, axes=FALSE, xlim=c(0, top), space=0, horiz=TRUE)
par(oma=c(3,3,0,0))
mtext(xlab, side=1, line=1, outer=TRUE, adj=0, 
      at=.8 * (mean(x) - min(x))/(max(x)-min(x)))
mtext(ylab, side=2, line=1, outer=TRUE, adj=0, 
      at=(.8 * (mean(y) - min(y))/(max(y) - min(y))))
}

#with your code#

with(chol, scatterhist(chol$AGE, chol$WEIGHT, xlab="AGE", ylab="WEIHGT"))